Two-Dimensional Inversion and Interpretation of MagnetoteSluric Data in a Seismic Active Area of Northern Part of North China

摘要

Two advanced techniques, decomposition of the magnetotelluric (MT) impedance tensor and Rapid Relaxation two-dimensional Inversion (RRI), have been successfully applied to the newly observed MT data. The resultant 2-D electrical structure along Yanggao-Rongcheng profile, which passes through several major tectonic units in northern part of North China, shows that the electrical conductivity structure in the shallow depth agrees well with the regional geological and geophysical information. High conductivity zone is detected discontinuously within middle -lower crust, with obviously lateral inhomogeneity in the crust. Highly conductive zone is also found in the upper mantle. Characteristic distribution of conductivity around the earthquake focal area in the crust is discussed.